Download File from Specific Location in Asp.net MVC

Download File from Specific Location in Asp.net MVC

  
  public async Task<ActionResult> GeneratePayment()
        {
           
           string fileName = "Book.pdf";
           
            try
            {
                if (!string.IsNullOrEmpty(fileName))
                {
                    Response.ContentType = "Application/pdf";
                    Response.AppendHeader("Content-Disposition", "attachment; filename=" + fileName);
                    Response.TransmitFile(Server.MapPath("~/Files/" + fileName));
                    Response.End();
                    ViewBag.Success = "Downloaded Successfully";
                    ViewBag.ReturnUrl = Url.Action("GeneratePayment", "ControllerName");
                }
                else
                {
                    ViewBag.Success = "Sorry! No File available.";
                    ViewBag.ReturnUrl = Url.Action("GeneratePayment", "ControllerName");
                }
            }
            catch 
            {

            }

            return View("Message");

        }
        
        //Get The Things More Dynamic when You Don't Know The ContentType of The File.
        
        
        
        public async Task<ActionResult> GeneratePayment()
        {
           
          string fileName = "Book.pdf";
          string fileExtension = ".pdf";
           
            try
            {
                if (!string.IsNullOrEmpty(fileName))
                {
                    Response.ContentType = GetContentType(fileExtension);
                    Response.AppendHeader("Content-Disposition", "attachment; filename=" + fileName);
                    Response.TransmitFile(Server.MapPath("~/Files/" + fileName));
                    Response.End();
                    ViewBag.Success = "Downloaded Successfully";
                    ViewBag.ReturnUrl = Url.Action("GeneratePayment", "ControllerName");
                }
                else
                {
                    ViewBag.Success = "Sorry! No File available.";
                    ViewBag.ReturnUrl = Url.Action("GeneratePayment", "ControllerName");
                }
            }
            catch 
            {

            }

            return View("Message");

        }
        
        private string GetContentType(string fileExtension)
        {
            if (string.IsNullOrEmpty(fileExtension))
                return string.Empty;

            string contentType = string.Empty;
            switch (fileExtension)
            {
                case ".htm":
                case ".html":
                    contentType = "text/HTML";
                    break;

                case ".txt":
                    contentType = "text/plain";
                    break;

                case ".doc":
                case ".rtf":
                case ".docx":
                    contentType = "Application/msword";
                    break;

                case ".xls":
                case ".xlsx":
                    contentType = "Application/x-msexcel";
                    break;

                case ".jpg":
                case ".jpeg":
                    contentType = "image/jpeg";
                    break;

                case ".gif":
                    contentType = "image/GIF";
                    break;

                case ".pdf":
                    contentType = "application/pdf";
                    break;
            }

            return contentType;
        }